Individuals lacking ridge detail: A case study in adermatoglyphia

Adermatoglyphia is a very rare autosomal‐dominant condition that is genetically inherited and causes an individual to be born without conventional ridge detail on either their palmar or plantar surfaces (the fingers and palms of the hands and the toes and the soles of the feet). While adermatoglyphia has been the focus of medical and genetic research, no previous research has been conducted with regard to the forensic recovery and identification of marks from an adermatoglyphic individual. By observation of ridge detail donated by an adermatoglyphic subject, the study uses different methods in order to capture fingermarks (methods include: inked capture, livescan (biometric) capture, cyanoacrylate fuming, ninhydrin enhancement, and physical developer). Unusually, the purpose of this paper ends up presenting a number of examples of an absence of evidence; unsuccessful attempts made to capture and enhance fingerprint ridge detail. This is determined over a range of standard means including "live" donations by the adermatoglyphic subject onto the Livescan system, and enhancements of latent donations. The subject shows to leave either insubstantial fingermarks with no detail, or no mark whatsoever.     

Cuticular hydrocarbons as a tool for determining the age of Chrysomya rufifacies (Diptera: Calliphoridae) larvae

Calliphoridae are one of the most important insect groups encountered as evidence collected from a crime scene. Age determination of the immature stages of these necrophagous flies is an important step toward estimating the time of colonization and inferring a minimum postmortem interval (PMI_min) in most instances. To determine if the cuticular hydrocarbons could be used to establish whether the development stages yield characteristics profiles, allowing for age estimation, hydrocarbons were extracted from 1st and 2nd, as well as feeding and post‐feeding 3rd instar Chrysomya rufifacies, the hairy maggot blow fly. Extracted hydrocarbons were analyzed using gas chromatography coupled to mass spectrometry with the aim to investigate the changes in chemical profiles of each larval stage. A total of 23 compounds were identified with most of them being alkanes (65%) with carbon chain lengths of 9–33 carbons, alkenes (18%), and methyl‐branched alkanes (17%). All the hydrocarbons except pentadecane (C15), hexadecane (C16), and nonacosane (C29) showed significant differences in their expression throughout larval development. For 1st instars, nonane was the most abundant (17% of the total hydrocarbons content) compound. Accounting for 11% and 10% of the cuticular hydrocarbons, tricosane and pentacosane, respectively, were the notable hydrocarbons in 2nd instars. For post‐feeding 3rd instars, hentriacontane and tritriacontane were present with relative abundances 18% and 15%, respectively. On average, there was a shift from low to high molecular weight hydrocarbons as the larvae aged. These results indicate the change in hydrocarbons makeup as larvae age and could potentially be used to determine the age of immature C. rufifacies and hence aid in PMI_min estimations. However, future research is needed to validate these results under natural conditions in the field.     

Research on the local regional similarity of automatic fingerprint identification system fingerprints based on close non-matches in a ten million people database—Taking the central region of whorl as an example

The local regional similarity of fingerprints has always been a hot issue in the field of fingerprint research. With the increasing size of ten-print databases, the appearance of close non-matches (CNMs) in automatic fingerprint identification system (AFIS) candidate lists has attracted increasing attention from forensic science departments worldwide. In this study, three categories (high-, medium-, and low-level) of standards for CNMs were established and 60 whorl samples were marked with different numbers of minutiae to explore the occurrence and influencing factors of CNMs in AFIS candidate lists based on a ten million people database. The results showed that all prints could be found with their corresponding CNMs. The average occurrence rate of CNMs for every query was 52.7% in the top 100 lists, and the most similar CNM was exactly the same in the local area of 12 coincidence points. CNMs appeared more in the middle and lower parts of the central region of the whorl. Moreover, shorter C2C distances and the same finger number and hand led to more CNMs being inspected. CNMs with higher similarity required a more extensive regional area and smaller minutiae density. We concluded that CNMs have a high occurrence rate in large-scale databases and many factors are closely related to them. Fingerprint examiners and researchers need to strengthen their understanding of CNMs to avoid the occurrence of misidentification like the Madrid bombings.     

Heat and let dye: Part II – Rapid heat-fixing of blood traces

Blood-contaminated shoeprints and footmarks contain valuable operational information as they may bind an individual who stepped in the crime scene with the incident and not merely with the location. As determining the age of a bloodstain remains a challenge, while processing the scene, it is difficult to determine whether the blood is completely, or partially, dry. Thus, executing a dye staining protocol may wash these marks away as they might still be soluble. However, to meet this challenge, it is possible to fix blood marks using heat. This study aims to find a solution for floor surfaces covered by heavier blood traces (shoeprints and footmarks). For this purpose, a new pseudo-operating device was constructed for examining the blood-fixing process of both mentioned trace types. Two trials were performed with depletion marks. The results revealed that fully developed fresh and heavily blood deposits were obtained by heating to 200°C for 7.5 min using the fixing device, followed by a staining protocol using amido black solution. The achieved sharp resolution of the examined bloody prints demonstrates that in certain cases the dehydration mechanism of heating is preferred over precipitating the proteins attributed to 5-sulfosalycilic acid; thus, reducing the risk of washing blood evidence while processing the crime scene.     

Total Ion Spectra versus Segmented Total Ion Spectra as Preprocessing Tools for Gas Chromatography – Mass Spectrometry Data

Alignment of fire debris data from GC‐MS for chemometric analysis is challenged by highly variable, uncontrolled sample and matrix composition. The total ion spectrum (TIS) obviates the need for alignment but loses all separation information. We introduce the segmented total ion spectrum (STIS), which retains the advantages of TIS while retaining some retention information. We compare the performance of STIS with TIS for the classification of casework fire debris samples. TIS and STIS achieve good model prediction accuracies of 96% and 98%, respectively. Baseline removal improved model prediction accuracies for both TIS and STIS to 97% and 99%, respectively. The importance of maintaining some chromatographic information to aid in deciphering the underlying chemistry of the results and reasons for false positive/negative results was also examined.     

Homicide Rates in Lithuania

Homicide rate in Lithuania between 2004 and 2013 decreased and reached an average of 6.7 per 100,000 people in 2013. The data regarding forensic autopsies of intentional homicide victims were obtained from the State Forensic Medicine Service. Spearman's correlation test was used to assess trends in the homicide rates. A significant correlation was observed between homicide distribution and the following variables: Lithuania's gross domestic product (r = ?0.85, p = 0.003), the number of alcohol intoxication cases of victims (r = 0.97, p < 0.05). After regression model adjustments, these variables remained significantly associated with the homicide distribution (p < 0.05). 73% of victims were men, with a mean age of 45.5 ± 15. Alcohol intoxication was present in 58% of victims. 66% of homicides were carried out indoors, 57% in urban area. The presented findings help decide which prevention programs may be the most effective in homicide rate reduction.     

Body Morph: Feasibility Testing of an Interactive CD-ROM to Teach Young Adolescents about Puberty

The aim of this pilot study was to examine the feasibility of an interactive computer program among 34 sixth and seventh grade children and to assess the potential for knowledge acquisition about puberty. Based on a developmental self-esteem approach to teach children about their bodies, the Body Morph program was designed to maximize the educational experience by: (1) tailoring puberty information to boys or girls, and (2) creating a confidential experience. Preliminary results indicated that students significantly improved their knowledge about puberty after using the program. Satisfaction among boys and girls for this type of educational approach suggests that it is a compelling format from which to learn about puberty.This research project was funded with the support of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) 1R43DK061269-01A2 to develop an educational computer program to improve body image in middle schoolers.     

16 X-chromosome STR loci frequency data from a German population

Allele frequencies for 16 X-linked STRs, suitable for forensic purposes, were obtained from a sample of unrelated German individuals (male and female). The presented data show also repeat sequence structures and statistic parameters describing there information content.     

A comprehensive ATR-FTIR spectroscopic analysis for the identification and differentiation of lip balms

Lip balm may be encountered as physical evidence in cases involving sexual assaults, homicides, and kidnappings. Lip balm can be used as corroborative evidence by providing a potential link between the victim, accused, and the crime scene. For lip balms to be used as evidence, it is important to understand the diversity and their aging process under different conditions. Therefore, in this study, ATR-FTIR spectroscopy in conjunction with chemometric tools such as principal component analysis (PCA) and linear discriminant analysis (LDA) has been used for the objective identification and differentiation of 20 brands of lip balms. Moreover, lip balms on different substrates and wearing effects over time were also investigated. The results show that the PCA-LDA training accuracy was 92.5%, whereas the validation accuracy comes out to be 83.33%. A blind study using pristine samples was also performed which resulted in 80% PCA-LDA accuracy. PCA-LDA prediction of samples on various substrates showed a higher chemometric prediction accuracy for nonporous substrates (glass, plastic, and steel), than for porous substrates (cotton cloth, cotton swab stick, dry tissue paper, and white paper) for samples kept in room temperature and under sunlight for 15 days. The substrate study showed that the samples from various substrates could effectively generate respective spectra which can help in brand-level identification even after several days. The present method demonstrates a potential for lip balm samples to be used in forensic casework applications.     

The role of DNA in criminal indictments in Israel

In their investigations of criminal cases, law enforcement agencies rely heavily on forensic evidence. Numerous studies have examined the scientific and technological advancements of DNA testing, but little evidence exists on how the availability of DNA evidence influences prosecutors' decisions to move cases forward in the criminal justice system. We created a new database by juxtaposing data from the Forensics Division of the Israel Police, which recorded the presence (or not) of DNA profiles in criminal cases (n = 9862), and data on the indictment decision for each case (2008–2019). Rates of indictments are computed for each case, and trend lines are used to present variations in the rates of indictment decisions with and without DNA profiles. Approximately 15% of all criminal cases without DNA presented to the prosecutor's office are subsequently prosecuted, compared with nearly 55% of cases with DNA profiles. The presence of DNA evidence influences the prosecutor's decision to move a case forward in the criminal justice system. Utilizing a scientific approach to prosecute offenders is a welcome development; however, DNA evidence is not infallible, and caution must be exercised in regard to DNA's overuse in the legal system.